Glucose uptake in chicken fibroblasts. The glucose binding factor we found in normal and malignant cells will be isolated in sizeable amounts to characterize it chemically. Binding being presumably the first step in a chain of reactions in the membrane, it will be followed up by attempts to preserve the components of the transport system, using short-term isolation procedures. The serum-like stimulation of glucose uptake by binding factor on starved cells makes a comparison between the two effects desirable. Polypeptide synthesis. In thioester-linked tyrocidine synthesis we plan to work out the mechanism of the function of a small pantetheine-protein as cofactor in amino acid polymerization. The recently observed manner in which pantetheine is bound to the tyrocidine synthesizing enzymes suggests new approaches to confirm its proposed function of catalyzing the new addition of enzyme-bound amino acid to the elongating polypeptide chain. Biosynthesis of guanosine 5',3'-polyphosphates in bacilli. Some members of this group were found to contain a new ribosome-independent enzyme for ppGpp and pppGpp synthesis. The enzymes in the different organisms are now being purified, to be compared with each other and the classical ribosome-dependent E. coli enzyme (stringent factor).